When hardening or tempering complex shapes such as airfoils, especially for localized treatments, conventional methods such as direct flame impingement hardening or direct induction can locally overheat areas impacting material properties by enlarging grain size or localized melting. Areas which contain thin section features in association with thicker sections are particularly vulnerable.
Historically parts have been locally heat treated by a gas flame (often to harden the part, but tempering or softening may also be achieved) or by direct treatment with induction heating methods. This direct or local treatment can be difficult to control especially when the parts have complex shapes with a mix of fine or thin cross sections along with thicker sections.
A susceptor is an apparatus used for the indirect heating of materials such as polymers and ceramics which are not electrically conductive. The susceptor may be heated by induction, or other methods. Heat from the susceptor is then transferred to the target work material by thermal conduction, convection or radiation. A typical susceptor material may include, e.g., graphite, silicon carbide, molybdenum, stainless steels or any thermally conductive material with suitable thermal properties. What is needed is a proper selection of the susceptor material for the heat treatment cycle, an appropriate shape and mass for the susceptor, a method for heating a susceptor to the target temperature and then a means for exposing the susceptor to the component part for the localized heat treatment process.
Intended advantages of the disclosed systems and/or methods satisfy one or more of these needs or provide other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs.